Mechanisms of Monotonic and Cyclic Deformation

本提案研究金属的非弹性变形， 疲劳和蠕变对结构演变的相关影响， 这又影响变形过程。 程序 包括三个相关的研究：（1）重新加载测试，以评估 结构的演化， 门槛值和非热应力参数;（2）应变率变化 研究恒定结构变形动力学的试验 在疲劳过程中;和（3）应力变化试验， 区分蠕变的不同理论处理方法， 弥散强化合金 基于机械的模型是 为提供变形的定量描述而开发。 %%% 本研究的主要目的是了解 非弹性变形过程，以延长操作 现有结构材料的环境，开发新的 材料性能得到改善，并获得更好的控制 成形和制造操作。

This proposal examines inelastic deformation in metals and associated effects of fatigue and creep on structure evolution, which, in turn, influences the deformation process. The program consists of three related studies: (1) reloading tests to assess the evolution of structure as represented by the mechanical threshold and athermal stress parameters; (2) strain rate change tests to study the kinetics of constant structure deformation during fatigue; and (3) stress change tests designed to discriminate between different theoretical treatments of creep in dispersion-strengthened alloys. Mechanistically-based models are developed to provide quantitative descriptions of deformation. %%% The primary goal of this research is to gain understanding of inelastic deformation processes in order to extend the operating environments of existing structural materials, to develop new materials with improved properties, and to gain better control of forming and manufacturing operations.